A tractor/baler combination is used in agriculture to take up crop lying or standing on a field and to press and bind it into a bale. An operator sits at an operator station of the tractor and steers the tractor along the crop. In prior art systems, the operator needs to control a number of functions of the baler and the tractor, like stopping the tractor once a bale is ready for ejection, opening a rear door of the baler to allow a bale to eject, closing the door and resuming driving. The described duties are difficult for an inexperienced operator and fatiguing for an operator who has driven and controlled the tractor/baler combination for a longer time.
EP 1 813 146 A describes an automated tractor/baler combination in which the tractor is automatically stopped once a bale has reached its desired size. The door is then opened once the tractor operator has given a bale ejection signal via a keyboard, such that the operator has the chance to bring the tractor and baler into a suitable position when the actual position is not suited to eject a bale, e.g. on uneven terrain. After the bale was ejected, another signal from the operator is awaited from the operator before the baling operation is resumed. The operation of this tractor/baler combination is thus not entirely automatic, but relies on input from the operator.
Opening the door upon a confirmation signal from the operator involves a certain risk of accidents, since he/she might not see if there is an obstacle, like a person, standing behind the door that could be hit or injured by the opening door.